Sarcoidosis

DR FAROOQ

Introduction

Sarcoidosis is a multisystem granulomatous disorder of unknown cause.
Characterised by non-caseating granulomas in affected organs.
Most commonly affects lungs, lymph nodes, skin, and eyes.
Can present acutely or chronically.

Epidemiology

Worldwide distribution, more common in northern Europe and African Americans.
Peak incidence: young adults (20–40 years).
Slight female predominance.
Genetic and environmental factors.

Pathophysiology

Granulomatous inflammation with non-caseating granulomas.
Exaggerated immune response to unknown antigen.
CD4+ T cells and macrophages play key role.
Leads to organ damage and fibrosis in chronic cases.

Clinical Manifestations & Features

Pulmonary (>90%)

Most common site of involvement (~90%).
Dyspnea, dry cough, chest pain.
Bilateral hilar lymphadenopathy on chest X-ray.
May progress to pulmonary fibrosis.
Pulmonary fibrosis in chronic disease.

It is restrictive lung disease

Cutaneous (25-35%)

Erythema nodosum.
Lupus pernio.
Maculopapular lesions / maculopapular rash.

Ocular (10-25%)

Anterior uveitis / uveitis.
Conjunctival granulomas / conjunctivitis.
Lacrimal gland enlargement.
Risk of visual impairment if untreated.

Cardiac (5-10%)

Conduction defects.
Cardiomyopathy.
Arrhythmias.
Sudden cardiac death.

Neurological (5-10%)

Cranial nerve palsies (especially facial nerve).
Peripheral neuropathy.
Seizures, encephalopathy.

Metabolic (10-15%)

Hypercalcemia.
Hypercalciuria.
Kidney stones, nephropathy.

Hepatic & Splenic

Hepatosplenomegaly.

Renal

Hypercalcemia.
Nephrocalcinosis.

General/Constitutional Symptoms

Can be asymptomatic (incidental finding on chest X-ray).
Constitutional symptoms: fever, fatigue, weight loss, night sweats.
Organ-specific manifestations depend on site of involvement.

Investigations & Diagnosis

Chest X-rayx

Bilateral hilar lymphadenopathy, interstitial changes.

Staging of Sarcoidosis on the Basis of Chest Radiographs

STAGE	Description	Frequency
STAGE 0	No abnormalities	5%–10%
STAGE 1	Lymphadenopathy (fig. A)	50%
STAGE 2	Lymphadenopathy + pulmonary infiltration (fig. B)	25%–30%
STAGE 3	Pulmonary infiltration (fig. C)	10%–12%
STAGE 4	Fibrosis	5% (up to 25% during the course of the disease)
![[Sarcoidosis_img-7.jpeg	227x174]]![[Sarcoidosis_img-8.jpeg	214x175]]![[Sarcoidosis_img-9.jpeg

HRCT (High-Resolution CT)

Pulmonary infiltrates, fibrosis.

Blood Tests

↑ serum ACE.
↑ calcium.
↑ ESR.

Biopsy

Non-caseating granulomas (diagnostic).
Exclude TB and fungal infections.

Diagnostic Criteria: Confirming Sarcoidosis

Clinical and Radiological Suspicion	Histopathological Confirmation	Exclusion of Other Granulomatous Diseases
Compatible symptoms and imaging findings (often incidental)	Non-caseating epithelioid granulomas in one or more organs	Rule out infections, malignancy, and other granulomatous disorders

Differential Diagnosis

Infections	Malignancies	Autoimmune
Tuberculosis, fungal infections, non-tuberculous mycobacteria	Lymphoma, lung cancer, metastatic disease	Granulomatosis with polyangiitis, eosinophilic granulomatosis

Other Differential Diagnoses:

Tuberculosis.
Lymphoma.
Fungal infections (e.g., histoplasmosis).
Hypersensitivity pneumonitis.
Vasculitis. Z

Clinical Syndromes

Löfgren Syndrome

Characterized by acute onset of:

Erythema nodosum.
Bilateral hilar lymphadenopathy.
Fever.
Arthritis.

Heerfordt Syndrome (Uveoparotid Fever)

Involves:

Uveitis.
Parotid gland swelling.
Fever.
Facial nerve palsy.

Management

Asymptomatic/mild cases may resolve spontaneously.
Corticosteroids: mainstay of treatment.
Immunosuppressants: methotrexate, azathioprine in resistant cases.
Symptomatic treatment for organ involvement.
Regular monitoring for complications.

Prognosis

Many cases resolve spontaneously within 2–5 years.
Chronic progressive disease in ~20%.
Poor prognosis with cardiac, neurological, or fibrotic lung involvement.

Summary

Sarcoidosis is a multisystem granulomatous disease of unknown cause.
Non-caseating granulomas in affected organs.
Common sites: lungs, lymph nodes, skin, eyes.
Diagnosis: biopsy + exclusion of infections.
Treatment: corticosteroids, immunosuppressants if needed.
Prognosis usually good, but variable.